U.S. Pat. No. 4,688,376 issued to Donald E. Wolfe, Sr. on Aug. 25, 1987 discloses an adjustable carriage for electric string trimmers which converts a string trimmer into a mower for small lawns. In order to free the trimmer from the carriage, the operator must physically detach the mechanism from the trimmer. A trimmer independent of any support mechanisms produces an uneven cut, while physically straining the operator. It is a highly valuable and efficient objective to develop a mechanism which could transform a hand held trimmer into a mower and convert it back into the independent trimmer without removing the conversion mechanism, thus improving the quality of the trimmer's operation, its safety, efficiency and functionality, and adapting it for trimming slanted banks smoothly and uniformly.
A number of U.S. patents have suggested the installation of wheels on string trimmers. See for example: U.S. Pat. Nos. 5,450,715; 5,222,750; 5,092,112; 4,879,869; 4,442,659; and 4,704,849.
These are all heavy, clumsy, awkward devices, lacking convenient adaptability between a wheels-deployed "mower" condition and the wheels-retracted "trimmer" condition.